cognōmen (noun N) : co-nomen.
* A name added to the nomen (or name of the gens), usu. the third word in order in the full name of each citizen; sometimes followed by a fourth, the agnomen, but in the class. per. including the agnomen, a Roman surname, family name, epithet (e. g. Cicero, Scipio, etc., Africanus, Asiaticus, etc.; cf. Quint. 7, 3, 27; freq. and class.): T. Manlius, qui Galli torque detracto cognomen (sc. Torquati) invenit,Cic. Off. 3, 31, 112; cf. id. Fin. 1, 7, 23: duo isti T. Roscii, quorum alteri Capitoni cognomen est,id. Rosc. Am. 6, 17; so with dat., Liv. 2, 33, 5; 32, 2, 7; Suet. Caes. 59; id. Aug. 7; id. Vit. 18; id. Claud. 26; Hor. S. 1, 3, 58; cf. Plaut. Pers. 1, 2, 8: sapientis habere,Cic. Lael. 2, 6: Augusti,Suet. Aug. 7: Arabiae felicis dare,Plin. 12, 13, 30, § 51: Felicem addere,id. 22, 6, 6, § 12: P. Crassus cum cognomine Dives,Cic. Off. 2, 16, 57: cognomen ex contumeliā traxerit,id. Phil. 3, 6, 16; so, ex vero dictum cognomen,Hor. S. 2, 2, 56: imponere alicui,id. ib. 2, 3, 26: Aristides... cognomine Justus sit appellatus,Nep. Arist. 1, 2: sumere ex aliquā re,Cic. Phil. 6, 4, 11: uti, id Clu. 26, 72.
* Meton., poet., or in post. Aug. prose sometimes, in gen. for nomen, a name: cognomina prisca locorum,Prop. 4 (5), 1, 69. so Verg. A. 1, 530; 3, 133; 3, 163; 3, 334; 3, 350; 8, 48; 8, 331 al.; Claud. B. Get. 555; Gell. 10, 12, 6.

s. TLL